Heap-based buffer overflow in Mozilla Network Security Services (NSS) before 3.19.2.3 and 3.20.x and 3.21.x before 3.21.1, as used in Mozilla Firefox before 45.0 and Firefox ESR 38.x before 38.7, allows remote attackers to execute arbitrary code via crafted ASN.1 data in an X.509 certificate.

It was found that Diffie Hellman Client key exchange handling in NSS 3.21.x was vulnerable to small subgroup confinement attack. An attacker could use this flaw to recover private keys by confining the client DH key to small subgroup of the desired group.

Use-after-free vulnerability in the PK11ImportDERPrivateKeyInfoAndReturnKey function in Mozilla Network Security Services (NSS) before 3.21.1, as used in Mozilla Firefox before 45.0, allows remote attackers to cause a denial of service or possibly have unspecified other impact via crafted key data with DER encoding.